Published online by Cambridge University Press: 01 April 2022
Einstein's papers on relativity, quantum theory, and statistical mechanics were all part of a single research program; the aim was to unify mechanics and electrodynamics. It was this broader program–which eventually split into relativistic physics and quantum mechanics–that superseded Lorentz's theory. The argument of this paper is partly historical and partly methodological. A notion of “crossbred objects“–theoretical objects with contradictory properties which are part of the domain of application of two different research programs–is developed that explains the dynamics of revolutionary theory change.